DEOXYCYTIDINE KINASE MESSENGER-RNA LEVELS IN LEUKEMIA-CELLS WITH COMPETITIVE POLYMERASE CHAIN-REACTION ASSAY

Deoxycytidine kinase (dCyd kinase) is important for the phosphorylatio n of several different nucleoside antimetabolites. To understand the s ignificance of dCyd kinase levels in chemotherapy, dCyd kinase mRNA le vels were evaluated in several cells with a quantitative competitive p olymerase chain reaction (PCR) assay. dCyd kinase catalytic activity a nd intracellular ara-CTP production were also compared with the levels of dCyd kinase mRNA. The assay was able to show: (i) that dCyd kinase catalytic activity and dCyd kinase mRNA levels were correlated in cel ls; (ii) that dCyd kinase mRNA levels were more sensitive in lower lev els of 10 amol/mu g of total RNA; and (iii) in cytosine arabinoside (a ra-C)-resistant cells, both dCyd kinase mRNA levels and intracellular ara-CTP levels were lower compared with levels in sensitive cells. The PCR assay for dCyd kinase mRNA could be useful in the selection and m onitoring of patients treated with nucleosides that are activated by t his enzyme. Copyright (C) 1996 Elsevier Science Ltd.